Previously, Angular devtools would mistakenly traverse the same DOM elements multiple times while doing traversal for the component tree explorer. This error case would occur when more than 1 Angular application root component was present on the same page and in distinct DOM branches.
Some example cases that did work previously:
```html
<app-root>
...
</app-root>
```
```html
<app-root>
...
<app-root-2></app-root-2>
...
</app-root>
```
An example of where it would enter the irregular behaviour
```html
<app-root>
...
</app-root>
<app-root-2>
...
</app-root-2>
```
Now, we properly ignore duplicate DOM paths when looking for application and non-application root component to begin the Angular DevTools component discovery logic.
PR Close#62719
This commit runs tslint --fix with the angular/angular tslint configuration on the files inside the devtools codebase.
Notably, the file-header rule in `tslint.json` was missing a default attribute. This commit adds that default attribute and sets it to the
license header that is present in all files in this repo. After running tslint --fix with this default added, this commit added the license header to all files in the devtools directory. Note for the reviewer: the automatically added license headers were added as comments with the "/*!" prefix. Since we want these comments removed in builds, and the rest of the codebase uses "/**", a simple find and replace was performed on the devtools directory to change these prefixes to "/**".
Formats the entire devtools directory with the ng-dev formatting tool. Previously we relied on prettier, so this commit also remove prettier from devtools' dependencies.
